Xylem 8100 Series Centrifugal Pumps AC2515 REV.C - Manual (Page 41)

FIGURE 34 – PRESSING IMPELLER ON SHAFT
NOTE: For impeller with replaceable rings,
heat each new ring (0-004-0) (approximately
300°F-400°F for bronze) and slide onto the
impeller. Using gloves, hold rings against the
impeller shoulder until they cool.
3. From the outboard end, using gloves,
slide the heated impeller on the shaft (3-
007-0) against the shaft shoulder, and
install retaining ring (3-915-1).
4. Lubricate and roll an O-ring (3-914-2) into
the groove in each casing ring (3-003-9)
and slide the casing rings over the
impeller.
5. Thoroughly clean the stuffing boxes (3-
073-9) to prevent dirt from entering the
seal during startup.
6. Press the stationary seats (0-400-0) of the
mechanical seals into both stuffing boxes,
with the lapped surface facing the
impeller. Lightly lubricate the stuffing box
bore to ease assembly (See Figure 35).
FIGURE 35 – INSTALLING STATIONARY SEAT
7. Press a new lip seal (3-177-9) into each
stuffing box. Before installing the lip seal,
lubricate the seal lip with a lightweight oil.
NOTE: Lip seals should seat against
machined shoulder bracket.
NOTE: Seal lip should point away from the
bearings (3-026-3 and -4), if the bearings are
grease lubricated, and towards the bearings,
if the bearings are oil lubricated.
8. Lubricate and roll O-ring (3-914-1) into the
groove in each stuffing box.
NOTE: STEPS 9 THROUGH 21 MUST BE
COMPLETED WITHIN 10 TO 12 MINUTES
TO ASSURE PROPER PLACEMENT OF
MECHANICAL SEAL. THE MECHANICAL
SEAL USED HAS AN ADHESIVE ON THE
INNER DIAMETER OF THE ELASTOMER.
THE ROTATING ELEMENT MUST GO INTO
THE CASING BEFORE THIS SEALANT
BONDS TO SLEEVE.
9. Lightly coat the outboard end of the shaft
with STP motor oil treatment or equal and
slide the mechanical seal head (0-400-0)
onto the shaft (See Figure 36). NOTE:
Standard mechanical seal for this
arrangement is a modified John Crane,
Type 21 Mechanical Seal.
10. Slide one of the stuffing boxes on the
shaft so that the shaft end extends
through the mech-anical seal area, but
does not enter the lip seal. This will permit
installation of deflector (3-136-9).
FIGURE 36 – SEAL HEAD INSTALLATION
11. Slide the deflector over the shaft end; then
carefully push the shaft end through the lip
seal and slide stuffing box fully onto the
shaft. COMPRESS THE SEAL SPRING
ONLY AS FAR AS REQUIRED TO
INSTALL BEARINGS.
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